giúp mình với ạ a, A= (a+b)^3 + (a - b )^3 b, B= ( x - y )^3 - 3.(x - y ) z^ 2 - z^3 c, C= 6.(c -d ).(c+d) ^2 + 12. ( c-d)^2. (c+ d) + ( c+d)^3 + 8 ( c-d) ^3 d, D = ( u-v)^3 + 3uv(u+v) e, E= 3( c-2d).( c+2d) ^2 + 3(c-2d)^2.(c+2d)+ (c+2d)^3 + (c _ 2d)^ 3